Perhaps you should try some spelling variations:
credit training » credit rationing, credit rating, credit granting
credit trading » credit rating, credit standing, credit creating
cost coping » post coping, port coping, cost computing
dong nana » dong nan, dong yang
nana yama » nana yaa
yama hua » ya hua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: dong nana yama hua ((credit training) OR (credit trading)) ((cost coping) OR (cost housing)) shu ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "dong nana yama hua ((credit training) OR (credit trading)) ((cost coping) or (cost housing)) shu ;~".
• Adding a wildcard symbol may retrieve word variants: dong nana yama hua ((credit training) OR (credit trading)) ((cost coping) or (cost housing)) shu ;*.